Surging out of the sea, the Bass Rock has for centuries borne witness to the lives that pass under its shadow on the Scottish mainland. And across the centuries, the fates of three women are inextricably linked to this place and to each other. Sarah, accused of being a witch, is fleeing for her life. Ruth, in the aftermath of the Second World War, is navigating a new marriage and the strange waters of the local community. Six decades later, Viv, still mourning the death of her father, is cataloguing Ruth's belongings in the now-empty house. As each woman's story unfolds, it becomes increasingly clear that their choices are circumscribed, in ways big and small, by the men who seek to control them. But in sisterhood there is also the possibility of survival and a new way of life.